Is there a simple way to add a simple rectangle to a Custom View without using a custom NSView subclass for it? Something along the lines of:
Assign an IBOutlet (let's call it colorWheelView) of NSView type to the CustomView
In my NSViewController's initWithNibName use it to change draw the rectangle:
// pseudocode
self.colorWheelView.addRectangle(myRectangle);
self.redraw()
The only way I've seen it done (on this site, and in my book Cocoa Programming for Mac OSX, pp. 241) is by making a custom class for the Custom View and modifying its drawRect method... Is this really the only way to accomplish this?
Edit: not sure why formatting is not being rendered correctly. I'm trying to fix it.
It really isn't all that hard to roll your own..
Just add an NSArray property to your NSView subclass, then in your drawRect method draw them either manually or using one of the NSRectFillList* methods provided by AppKit already.
(Beware: those take a plain C array, not an NSArray).
You wouldn't want to manually trigger the redraw from outside the view as in your sample code, though. To keep things consistent your addRectangle would trigger a redraw of the view itself e.g. by calling setNeedsDisplay:.
Related
I've got my custom NSView with a bunch of custom buttons in it, the buttons are added as a subView in the NSView's drawRect method.
Now I'm finding that after pressing a button the drawRect of the parent view is repeatedly called. Sometimes it only stops when I quit the app - I know this from a simple log statement in drawRect.
Now I know there are probably bigger architectural issues in my app causing this, where do I go to begin tracking down what's causing this view to be repeatedly redrawn?
Thanks!
First of all you shouldn't be adding subviews in drawRect:.
Are you doing any custom drawing or are you just adding subviews? If you're not doing any drawing, you should not implement drawRect:.
You want to add the subviews in initWithFrame: and then you want to set the frames of the subviews in layoutSubviews based on self.bounds.
If you have any questions, feel free to ask.
EDIT: Just realized that you were asking about NSView and not UIView. I've never used NSView, but perhaps they work similarly.
EDIT 2: I read a bit about NSView and it doesn't seem to have layoutSubviews. Perhaps you should set the frames in drawRect:? I'm still pretty sure you don't want to add subviews in drawRect:.
I am pretty new to coding and would like to know how to switch XIB views on a button click. IS there also anyway to add animation when switching?
Thanks,
Kevin
this is totally possible, but there are a few things you'll need to do. I imagine you are already familiar with connecting outlets to objects in your XIB, so the first thing you need to do is create the custom views in your XIB and connect them to outlets in your appDelegate. I suggest that one of the views be dragged into the window and one one be outside the window. That way, when the window loads, it already has one of your custom views as a subview. This just makes it easier to get started.
Then you're going to write an IBAction in the appDelegate and connect it to your button. Assuming that one of the custom views is already being hosted by the window, the IBAction should send a replaceSubviewWith message to the window's contentView animator like this [[window.contentView animator] replaceSubview:firstView with:secondView]; where firstView and secondView are the pointer/outlets that you declared and connected to the views in your XIB.
This is sending the animator proxy of the window's content view a message which tells it to replace the old subview with the new one. The reason for sending the message to the view's animator proxy (and not the view itself) is that the transition will be carried out with the deafult CATransitionAnimation. Because you want it to be animated, right?
The reason why you shouldn't remove one subview and then add another is because animating the removal of a subview is actually quite tricky and requires the implementation of the delegate method animationDidEnd. This is because executing an animation on a view that has been removed from the view heirarchy does not make sense. I don't know why Apple hasn't changed this, but for now it will be one of the enduring quirks of CoreAnimation.
Let me know if that helps. I am happy to clarify! And welcome to Cocoa!
An easy way to do this is to use a tabless NSTabView- you can lay everything out in IB so the pain is minimal.
What's the minimum implementation needed to make a custom NSView with an editable text area? I assume NSTextFieldCell can be used for this. I've succeeded in drawing the cell in the view (which is straightforward), but making it editable seems to require a more complicated coordination between the view and the cell. Is there sample code available somewhere?
Update. I should have made clear that my longer-term goal is to have many more editable text areas on the same view. AFAIU it is better to use cells in that case as they are more light-weight than full-blown views. My updated question is: What's the minimum implementation needed to make a custom NSView with an editable text area using an appropriate NSCell?
What's the minimum implementation needed to make a custom NSView with an editable text area?
Make an NSView.
Put an NSTextField in it.
Remember, NSViews (custom or otherwise) can contain other NSViews, and an NSTextField is a kind of NSView.
If you don't want code outside the custom view class to know about the text field, and it probably shouldn't, the custom view can create the text field and add it to itself as a private implementation detail. To do this, simply don't expose the text field in the custom view class's #interface (aside from the instance variable declaration, which is unavoidable).
The custom view should, of course, not draw wherever it put its text field. It could draw there, but the text field would cover it.
I assume NSTextFieldCell can be used for this.
Yes, if you don't mind reimplementing NSTextField. Adding an NSTextField as a subview of your view is much easier.
If you want to make a grid of text fields (with a dynamic number of them, perhaps), use an NSMatrix of NSTextFieldCells. You can, of course, add the NSMatrix as a subview of your custom view.
If you want to edit a text cell just call editWithFrame:inView:editor:delegate:event: on the cell object. This method requires the NSEvent that started the editing, so you can only call this from an event handler. There also is selectWithFrame:inView:editor:delegate:start:length: which sets up the field editor with an selection. You can use this if you need to start the editing from outside of an event handler.
After the user is done editing you need to call endEditing: on your cell.
has anyone an idea if it is possible to create ellipse or polygon buttons in IB?
Directly, not without a library.
You can, however, create an NSView subclass which performs your shape drawing for you. You will need to implement the mouse events to perform clicks correctly. Drop an NSView on your window, set its class in the inspector to your custom-drawn NSView subclass, and you're set. Check out this tutorial.
You could also create a custom control, derived from NSControl. Check out this documentation.
Will the individual UML diagram shapes be NSView subclasses or NSBezierPaths? How are the diagrams created and managed?
One way to do this is to:
Create a document-based app
Design model classes for the different objects the end-user will be able to draw in your canvas, all sharing one abstract superclass
In your CanvasView class, implement drawRect and have it call the NSDocument subclass, or for more granular classes it's viewcontroller, to get all the objects that should be drawn in the right order to draw them.
For each of these objects, call a drawInteriorInView:rect: method or something similar that they all have implemented, from within your CanvasView's drawRect: implementation.
The advantage of such a granular design is that you can decide to replace NSBezierPath drawing with straight CoreGraphics calls if you find a need to do so, without having to completely re-architect the app.
Typical Cocoa controls, like for instance a tableView, implement a bunch of different drawing methods, one for the background, one for the gridlines, etc. etc. all of them called (when applicable) from the view's drawRect:.
Or you could of course look at GCDrawKit, which seems to have a pretty functional implementation. Especially check out the sample app that comes with it.
Have you looked at OmniGraffle? It may do what you need.
[non-programming-related answer...]
Have you looked at the Sketch example project, found in /Developer/Examples/AppKit? It should get you at least halfway to where you're going.
You would typically start with an NSView subclass to represent your "canvas" and handle drawing and mouse/keyboard events. You would probably use NSBezierPath inside your drawing methods to fill and outline the shapes. Depending on how complex the drawing code is, you might put everything in your NSView subclass, or make an NSCell subclass that would take some work out of the NSView. In either case you would want to define a data source protocol (or create bindings) to provide data to the NSView from the objects in your data model which represent UML items.
Core Animation would be worth considering too, although I would start with NSView at the beginning, at least for a simple prototype.